babernet_1 :
http://www.itworld.com/hardware/294623/intel-hopes-double-ultrabook-battery-life-haswell-chip
That would only apply to the "ultra low power" versions of the mobile Haswell CPUs which consumes 10w. If it is going to be anything like the Ivy Bridge "Y" series, then clockspeed will be pretty low in comparison to other typical Haswell mobile CPUs. Additionally, the "Y" series has the lowest clocked Intel HD 4000.
I will speculate that the Haswell "Y" series CPUs will have a low clocked version of the Intel HD 4600 (GT2), not the Intel HD 5000 (GT3) which has been speculated to be up to 100% faster than the Intel HD 4000.
Waiting for Haswell is a good idea if long battery life is extremely important. However, gaming laptops will not have the "Y" series CPU. They will have Haswell CPUs that will consume 15w - 17w if looking at ultrabooks. The 25w - 35w dual Haswell CPUs will be found typical laptops including the average gaming laptop. The quad core i7 Haswell CPUs will probably range from 35w - 45w.
Other than the "ultra low" version, I don't really see a dramatic increase in battery life, because the difference in power consumption of "typical" mobile Haswell CPUs vs. Ivy Bridge CPUs will not be that much.
I'll need to do a bit more research on Haswell's mobile CPU power consumption to provide a better answer. But I think given the little information that I have read so far, my opinion regarding battery life seems reasonable.